Compute the fraction of raster cells covered by a polygon

```
# S4 method for RasterLayer,sf
coverage_fraction(x, y, crop = FALSE)
# S4 method for RasterLayer,sfc_MULTIPOLYGON
coverage_fraction(x, y, crop)
# S4 method for RasterLayer,sfc_POLYGON
coverage_fraction(x, y, crop)
# S4 method for SpatRaster,sf
coverage_fraction(x, y, crop = FALSE)
# S4 method for SpatRaster,sfc_MULTIPOLYGON
coverage_fraction(x, y, crop)
# S4 method for SpatRaster,sfc_POLYGON
coverage_fraction(x, y, crop)
```

## Arguments

- x
a (possibly empty) `RasterLayer`

whose resolution and
extent will be used for the generated `RasterLayer`

.

- y
a `sf`

object with polygonal geometries

- crop
if `TRUE`

, each generated `RasterLayer`

will be
cropped to the extent of its associated feature.

## Value

a list with a `RasterLayer`

for each feature in `y`

.
Values of the raster represent the fraction of each
cell in `x`

that is covered by `y`

.

## Examples

```
rast <- raster::raster(matrix(1:100, ncol=10), xmn=0, ymn=0, xmx=10, ymx=10)
poly <- sf::st_as_sfc('POLYGON ((2 2, 7 6, 4 9, 2 2))')
cov_frac <- coverage_fraction(rast, poly)[[1]]
```